Description: 金星是距离太阳第二近的行星，经常被称为地球的孪生兄弟。它是一颗岩石质的类地行星，半径略大于 6000 公里，约为地球半径的 95%，质量是地球质量的 0.815 倍。金星大气的密度是地球的 90 倍，它的主要成分是二氧化碳，还有浓厚的硫酸云层覆盖整个表面。厚重的大气层产生了非常强烈的温室效应，导致金星表面温度高达 460 摄氏度。

金星与太阳的平均距离为 1.08 亿公里，约为 0.72 个天文单位（日地距离）。它绕太阳公转一周需要224.7天。相较于遥远的恒星，金星绕着它的轴自转一周也需要很长时间；一个金星日相当于 243 个地球日。这比金星绕太阳运行一周的时间还要长。金星没有已知的卫星。

金星以罗马爱神维纳斯命名。由于它离太阳很近，因此在日出前或日落后的夜空中经常可以看到金星。在这种情况下，即使用肉眼观察，金星也非常明亮，传统上被称为晨星或昏星。用双筒望远镜可以看到，金星有与月亮相似的相位变化。

Related Terms:

• 天文单位
• 温室效应
• 太阳系
• 类地行星

Term and definition status: The original definition of this term in English have been approved by a research astronomer and a teacher
The translation of this term and its definition is still awaiting approval

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